Chimney Cap: The "DraftMaster Caps" are specially designed to create updraft that can make fires easy to start. It will exhaust through the top or the bottom of outer wall, which will allow for performance during vertical of wind shear conditions. Designed for square or round chimneys. Measure the outside length (L) and outside width (W) of the chimney (not the old cap size).

Please note that copper DraftMaster Cap might have stainless steel parts inside of it for strength and durability, but all show parts will be solid copper.